[Abagail]

Use strcat, and ShowDialogForPlayer.

Example:

pawn Код:

CMD:help(playerid, params[])
{
    new string[125]; // change this to suit your needs.
    strcat(string, "Line 1\n", sizeof(string));
    strcat(string, "Line 2\n", sizeof(string));
    ShowDialogForPlayer(playerid, -1, DIALOG_STYLE_MSGBOX, "Messagebox Title", string, "", "");
    return 1;
}

And use SendClientMessage for chat messages.